A wide variety of seals for use in machine systems have been developed over the years. Seals are commonly used to retain lubricating fluid, such as oil or grease, within fluid cavities of machine system components. Where the machine system components are rotatable relative to one another, relatively sophisticated seal designs may be used to provide a fluid seal at a rotatable interface. One seal design which has seen much commercial success over the years is known in the art as a metal face seal. Metal face seals typically include inner seal members or “seal rings,” which are each coupled with a separate machine component. The seal rings have abutting metal faces which can rotate relative to one another while sealing lubricating fluid within and/or among the associated machine components with minimal leakage.
One specific metal face seal design utilizes conical seal rings which include metal faces biased together via a biasing force generated by a compressible seal member, commonly referred to as a “toric” in reference to its generally toroidal shape. Outer seal members or “seal retainers” are typically positioned about the seal rings, with the torics compressed therebetween to provide a fluid seal between the respective inner and outer seal members. A conical shape of the seal rings allows compression of the torics to generate a biasing force to bias the faces of the seal rings together while simultaneously serving a sealing function between the respective inner and outer seal members. Metal face seals having this configuration can often be made with a relatively small number of parts without sacrificing efficacy. U.S. Pat. No. 6,550,588 to Hinton et al. discloses one example of a metal face seal having conical seal rings.
Despite widespread commercial success of the aforementioned type of seals, in at least certain applications there is room for improvement. On the one hand, it may be necessary to relatively highly compress the torics to ensure that they can continue to exert sufficient face loading on the seal rings as the torics lose some of their resiliency over time. This typically occurs due to relaxation of the toric material and/or decay. The relatively high initial compression, and therefore face loading, however, can reduce the capability of the seal to accommodate high rotational speeds. In other words, in a new seal assembly having relatively highly compressed torics, the faces of the seal rings may be biased together more tightly than is desired, resulting in relatively high friction between the seal rings and associated heat at high rotational speeds. Such seals also may be unable to accommodate much movement between the seal components due to the relatively highly compressed torics. Moreover, the conical components also tend to be relatively challenging to precisely machine.
The present disclosure is directed to one or more of the problems or shortcomings set forth above.